As a conventional self-propelled crushing machine, there has been known, as disclosed in Japanese Unexamined Utility Model Publication No. Sho 64-32744 and Japanese Unexamined Patent Publication No. Sho 63-77553, a machine in which a hopper, a crusher and a drive means are mounted on a vehicular chassis that is provided with a pair of left hand side and right hand side traveling bodies and in which a discharge conveyer 16 is provided so as to be capable of being raised up and lowered down between the left hand side and right hand side traveling bodies at a lower portion of the above mentioned vehicular chassis.
Such a self-propelled crushing machine can travel by itself by rotationally driving a crawler or wheels and can finely crush an object of crush such as concrete waste and so forth that are charged via a feeder into the hopper. It can further discharge the crushed pieces out of the vehicular chassis through the conveyor.
In a self-propelled crushing machine as disclosed in Japanese Unexamined Utility Model Publication No. Sho 64-32744, an object of crushing that is charged into a hopper is dropped by the hopper directly into a crusher. Since the object of crushing is then caused to fall by its own weight along the hopper, the amount thereof that is fed into the crusher is varied depending upon its own weight as well as the amount that is charged into the hopper, and sometimes it cannot be crushed with stability. In addition, the object of crushing may possibly be clogged within the hopper, making it impossible for it to be fed into the crusher.
Also, as disclosed in Japanese Unexamined Patent Publication No. Sho 60-139347, a feeder has been known for supplying an object of crushing into a crusher. More specifically, a feeder has been known in which a comb-like plate that is reciprocated obliquely up and down is used to conduct a screening of the sizes of objects of conveyance that are charged into a hopper and to feed them into a crusher.
While such a feeder is capable of screening the sizes of objects of conveyance, it is unable to control their amounts of feed. It has also been found to be undesirable in that the feeder may be supplying an amount that exceeds the ability for a crusher to crush, thus either bringing about a reduced efficiency of crushing by the crusher or acting to apply an unreasonable force to the crusher.